Flame-resistant polycarbonate moulding materials modified with graft polymers

ABSTRACT

Flame resistant graft polymer-modified polycarbonate molding compositions are described. The polycarbonate molding compositions comprise phosphorous compounds, and a coagulated mixture of flourinated polyolefins or precompound fluorinated polyolefins. Polycarbonate molding compositions according the present invention are flame retardant, and have desirable mechanical properties, e.g., notched impact strength and elongation at break.

CROSS REFERENCE TO RELATED PATENT APPLICATIONS

The present patent application claims the right of priority under 35U.S.C. 119 (a)-(d) and 35 U.S.C. 365 of International Application No.PCT/EP00/02242, filed 14 Mar. 2000, which was published in German asInternational Patent Publication No. WO 00/58395 on 5 Oct. 2000, whichis entitled to the right of priority of German Patent Application No.199 14 137.1, filed 27 Mar. 1999.

FIELD OF THE INVENTION

The present invention relates to flame resistant graft polymer-modifiedpolycarbonate moulding compositions containing phosphorus compounds andspecially prepared fluorinated polyolefins, which compositions exhibitexcellent flame retardancy and very good mechanical properties such asnotched impact strength, elongation at break and very good stresscracking behaviour.

BACKGROUND OF THE INVENTION

Diphosphates are known as flame retardant additives. JP 59 202 240describes the production of such a product from phosphorus oxychloride,diphenols such as hydroquinone or bisphenol A and monophenols such asphenol or cresol. These diphosphates may be used as flame retardants inpolyamide or polycarbonate. However, this document makes no reference toimproved stress cracking resistance due to the addition of theoligomeric phosphate to polycarbonate moulding compositions.

EP-A 363 608 describes flame resistant polymer blends prepared fromaromatic polycarbonate, copolymer or graft copolymer containing styrenetogether with oligomeric phosphates as flame retardant. It is mentionedin general terms that tetrafluoroethylene polymers may be added.

EP-A 0 767 204 describes flame resistant polyphenylene oxide (PPO) orpolycarbonate mixtures which contain a mixture of oligophosphates (ofthe bisphenol A (BPA) oligophosphate type) and monophosphates as theflame retardant. Elevated flame retardant contents give rise todisadvantageous mechanical properties (notched impact strength, stresscracking behaviour) and reduced heat resistance.

EP-A 0 611 798 and WO 96/27600 describe moulding compositions which, inaddition to polycarbonate, contain oligomeric, terminally alkylatedphosphoric acid esters of the BPA type. Due to the alkylation, elevatedcontents are required in order to achieve effective flame retardancy,which is highly disadvantageous for many applicational properties(mechanical properties, heat resistance).

EP-A 0 754 531 describes reinforced PC/ABS moulding compositions whichare suitable for precision components. Flame retardants which are usedalso include inter alia BPA type oligophosphates. The elevated fillercontents have a highly disadvantageous effect on mechanical properties,such as elongation at break or notched impact strength.

EP-A 771 851 describes moulding compositions which contain aromaticpolycarbonate; graft polymer based on diene rubber, SAN copolymer, aphosphate and tetrafluoroethylene polymers, wherein the polycarbonatehas differing molecular weights. Resistance to loss of impact strength,to heat and moisture is stated as the advantage.

EP-A 755 977 describes polymer blends prepared from aromaticpolycarbonate, graft copolymer having a rubber content of <25% as wellas oligomeric phosphates having an added content of <8% and an N valueof N=1-35 as flame retardant additives. Serious disadvantages withregard to flame retardancy may be expected due to the limitation of thecontent of phosphates as the flame retardant.

EP-A 747 424 describes thermoplastic resins which contain phosphatecompounds having a molecular weight of approx. 500 to 2000 and ofphosphate compounds having a molecular weight of approx. 2300 to 11000as the flame retardant, wherein numerous thermoplastic resins arelisted. The elevated molecular weights of the flame retardants may causedisadvantages relating to flame retardancy in this case too.

SUMMARY OF THE INVENTION

The object of the present invention is to provide flame retardant, graftpolymer-modified PC moulding compositions which are distinguished byvery good mechanical properties, elevated flame retardancy and very goodstress cracking behaviour combined with elevated heat resistance. Thesemoulding compositions are thus in particular suitable for thoseapplications in which contact with special media, such as for examplesolvents, lubricants, cleaning agents, may occur.

It has now been found that graft polymer-modified polycarbonate mouldingcompositions which contain phosphorus compounds and special preparationsof fluorinated polyolefins exhibit the desired range of properties.

The present invention accordingly provides graft polymer-modifiedpolycarbonate moulding compositions containing phosphorus compounds ofthe formula (I)

in which

R¹, R², R³ and R⁴ are mutually independently C₁-C₈ alkyl, optionallysubstituted by halogen, C₅-C₆ cycloalkyl, C₆-C₁₀ aryl or C₇-C₁₂ aralkyl,each optionally substituted by halogen and/or alkyl,

n are mutually independently 0 or 1,

q are mutually independently 0, 1, 2, 3 or 4,

N is 0.9 to 10, preferably 0.95 to 5, in particular 1 to 3,

R⁵ and R⁶ mutually independently mean C₁-C₄ alkyl, preferably methyl, orhalogen, preferably chlorine and/or bromine,

Y means C₁-C₇ alkylidene, C₁-C₇ alkylene, C₅-C₁₂ cycloalkylene, C₅-C₁₂cycloalkylidene, —O—, —S—, —SO, —SO₂— or —CO—,

and fluorinated polyolefins in the form of a coagulated mixture or as aprecompound.

DETAILED DESCRIPTION OF THE INVENTION

The fluorinated polyolefins are preferably used as a coagulated mixturewith at least one component selected from among polycarbonate, graftpolymer and (co)polymer, wherein the fluorinated polyolefin orpolyolefin mixture is mixed as an emulsion with at least one emulsion ofthese components and then coagulated, or as a precompound with at leastone of the stated components, wherein the fluorinated polyolefins orpolyolefin mixture is mixed as a powder with a powder or pellets of atleast one of these components and melt-compounded.

The thermoplastic moulding compositions preferably contain 0.5 to 20,particularly preferably 1 to 18 and in particular 2 to 16 parts byweight of phosphorus compound (I) or a mixture of phosphate compounds(I).

The thermoplastic moulding compositions preferably contain 0.01 to 3, inparticular 0.05 to 2, very particularly preferably 0.1 to 0.8 parts byweight of fluorinated polyolefins in the form of special preparations,as a coagulated mixture or precompound.

Preferred thermoplastic moulding compositions are those containing

A) 40 to 99, preferably 60 to 98.5 parts by weight of aromaticpolycarbonate and/or polyester carbonate

B) 0.5 to 60, preferably 1 to 40, in particular 2 to 25 parts by weightof graft polymer of

B.1) 5 to 95, preferably 30 to 80 wt. % of one or more vinyl monomers on

B.2) 95 to 5, preferably 20 to 70 wt. % of one or more graftingbackbones having a glass transition temperature of <10° C., preferablyof <0° C., particularly preferably of <−20° C.,

C) 0 to 45, preferably 0 to 30, particularly preferably 2 to 25 parts byweight of at least one thermoplastic polymer selected from the groupcomprising vinyl (co)polymers and polyalkylene terephthalates,

D) 0.5 to 20 parts by weight, preferably 1 to 18 parts by weight,particularly preferably 2 to 16 parts by weight of a phosphorus compoundof the formula (I)

 in which R¹ to R⁶, Y, n, N and q have the above-stated meaning,

E) 0.01 to 3, preferably 0.05 to 2, particularly preferably 0.1 to 0.8parts by weight of fluorinated polyolefins as

E.1) a coagulated mixture with at least one of components A to C,wherein the fluorinated polyolefin or polyolefin mixture E is mixed asan emulsion with at least one emulsion of components A to C and thencoagulated

or

E.2) as a precompound with at least one of components A to C, whereinthe fluorinated polyolefin or polyolefin mixture E is mixed as a powderwith a powder or pellets of at least one of components A to C andmelt-compounded.

Component A

Component A aromatic polycarbonates and/or aromatic polyester carbonateswhich are suitable according to the invention are known from theliterature or may be produced using processes known from the literature(c.f. in relation to the production of aromatic polycarbonates, forexample Schnell, Chemistry & Physics of Polycarbonates, IntersciencePublishers, 1964 and DE-AS 1 495 626, DE-OS 2232 877, DE-OS 2 703 376,DE-OS 2 714 544, DE-OS 3 000 610, DE-OS 3 832 396; in relation to theproduction of aromatic polyester carbonates for example DE-OS 3 077934).

Aromatic polycarbonates are produced for example by reacting diphenolswith carbonic acid halides, preferably phosgene, and/or with aromaticdicarboxylic acid dihalides, preferably benzenedicarboxylic aciddihalides, by the phase interface process, optionally using chainterminators, for example monophenols, and optionally using trifunctionalor greater than trifunctional branching agents, for example triphenolsor tetraphenols.

Diphenols for the production of the aromatic polycarbonates and/oraromatic polyester carbonates are preferably those of the formula (III)

wherein

A means a single bond, C₁-C₅ alkylene, C₂-C₅ alkylidene, C₅-C₆cycloalkylidene, —O—, —SO—, —CO—, —S—, —SO₂—, C₆-C₁₂ arylene, onto whichfurther aromatic rings optionally containing heteroatoms may be fused,or a residue of the formula (IV) or (V)

B in each case is C₁-C₁₂ alkyl, preferably methyl, halogen, preferablychlorine and/or bromine

x in each case mutually independently is 0, 1 or 2,

p is 1 or 0 and

R⁷ and R⁸ mutually independently, individually selectably for each X¹,mean hydrogen or C,-C₆ alkyl, preferably hydrogen, methyl or ethyl,

X¹ means carbon and

m means an integer from 4 to 7, preferably 4 or 5, providing that R⁷ andR⁸ are simultaneously alkyl on at least one atom X¹.

Preferred diphenols are hydroquinone, resorcinol, dihydroxydiphenols,bis-(hydroxyphenyl)-C₁-C₅-alkanes,bis-(hydroxyphenyl)-C₅-C₆-cycloalkanes, bis-(hydroxyphenyl) ethers,bis-(hydroxyphenyl) sulfoxides, bis-(hydroxyphenyl) ketones,bis-(hydroxyphenyl) sulfones andα,α-bis-(hydroxyphenyl)diisopropyl-benzenes together with thering-brominated and/or ring-chlorinated derivatives thereof.

Particularly preferred diphenols are 4,4′-dihydroxydiphenyl, bisphenolA, 2,4-bis-(4-hydroxyphenyl)-2-methylbutane,1,1-bis-(4-hydroxyphenyl)cyclohexane,1,1-bis-(4-hydroxyphenyl)-3,3,5-trimethylcyclohexane,4,4′-dihydroxydiphenyl sulfide, 4,4′-dihydroxydiphenyl sulfone togetherwith the di- and tetrabrominated or chlorinated derivatives thereof,such as for example 2,2-bis-(3-chloro-4-hydroxyphenyl)propane,2,2-bis-(3,5-dichloro-4-hydroxyphenyl)propane or2,2-bis-(3,5-dibromo-4-hydroxyphenyl)propane.

2,2-Bis-(4-hydroxyphenyl)propane (bisphenol A) is particularlypreferred.

The diphenols may be used individually or as any desired mixtures.

The diphenols are known from the literature or are obtainable usingprocesses known from the literature.

Chain terminators suitable for the production of the thermoplastic,aromatic polycarbonates are, for example, phenol, p-chlorophenol,p-tert.-butylphenol or 2,4,6-tribromophenol, as well as long-chainalkylphenols, such as 4-(1,3-tetramethylbutyl)phenol according to DE-OS2 842 005 or monoalkylphenol or dialkylphenols having a total of 8 to 20C atoms in the alkyl substituents, such as 3,5-di-tert.-butylphenol,p-iso-octylphenol, p-tert.-octylphenol, p-dodecylphenol and2-(3,5-dimethylheptyl)phenol and 4-(3,5-dimethylheptyl)phenol. Thequantity of chain terminators to be used is generally between 0.5 mol %and 10 mol %, relative to the sum of moles of the diphenols used in eachcase.

The thermoplastic, aromatic polycarbonates have weight average molecularweights (M_(w), measured for example by ultracentrifugation or lightscattering) of 10000 to 200000, preferably of 20000 to 80000.

The thermoplastic, aromatic polycarbonates may be branched in a knownmanner, preferably by incorporating 0.05 to 2.0 mol %, relative to thesum of diphenols used, of trifunctional or greater than trifunctionalcompounds, for example those having three and more than three phenolicgroups.

Both homopolycarbonates and copolycarbonates are suitable. Component Acopolycarbonates according to the invention may be produced by alsousing 1 to 25 wt. %, preferably 2.5 to 25 wt. % (relative to the totalquantity of diphenols to be used) of polydiorganosiloxanes havinghydroxy-aryloxy end groups. These are known (c.f. for example U.S. Pat.No. 3,419,634) or may be produced using processes known from theliterature. The production of copolycarbonates containingpolydiorganosiloxanes is described, for example, in DE-OS 3 334 782.

Preferred polycarbonates, apart from bisphenol A homopolycarbonates, arecopolycarbonates of bisphenol A with up to 15 mol %, relative to the sumof moles of diphenols, of other diphenols mentioned as preferred orparticularly preferred, in particular2,2-bis-(3,5-dibromo-4-hydroxyphenyl)propane.

Aromatic dicarboxylic acid dihalides for the production of aromaticpolyester carbonates are preferably the diacid dichlorides ofisophthalic acid, terephthalic acid, diphenyl ether 4,4′-dicarboxylicacid and 2,6-naphthalenedicarboxylic acid.

Mixtures of the diacid dichlorides of isophthalic acid and terephthalicacid in a ratio of between 1:20 and 20:1 are particularly preferred.

A carbonic acid halide, preferably phosgene, is additionally used as adifunctional acid derivative in the production of polyester carbonates.

Chain terminators which may be considered for the production of thearomatic polyester carbonates are, apart from the above-mentionedmonophenols, also the chlorocarbonic acid esters thereof and the acidchlorides of aromatic monocarboxylic acids, which may optionally besubstituted by C₁-C₂₂ alkyl groups or by halogen atoms, together withaliphatic C₂-C₂₂ monocarboxylic acid chlorides.

The quantity of chain terminators is in each case 0.1 to 10 mol %,relative, in the case of phenolic chain terminators, to the number ofmoles of diphenols and, in the case of monocarboxylic acid chloridechain terminators, to the number of moles of dicarboxylic aciddichlorides.

The aromatic polyester carbonates may also contain incorporated aromatichydroxycarboxylic acids.

The aromatic polyester carbonates may be both linear and branched in aknown manner (c.f. in this connection also DE-OS 2 940 024 and DE-OS 3007 934).

Branching agents which may be used are, for example, tri- orpolyfunctional carboxylic acid chlorides, such as trimesic acidtrichloride, cyanuric acid trichloride,3,3′,4,4′-benzophenonetetracarboxylic acid tetrachloride,1,4,5,8-naphthalene-tetracarboxylic acid tetrachloride or pyromelliticacid tetrachloride, in quantities of 0.01 to 1.0 mol % (relative todicarboxylic acid dichlorides used) or tri- or polyfunctional phenols,such as phloroglucinol,4,6-dimethyl-2,4,6-tri-(4-hydroxyphenyl)-2-heptene,4,6-dimethyl-2,4,6-tri-(4-hydroxyphenyl)heptane,1,3,5-tri-(4-hydroxyphenyl)benzene, 1,1,1-tri-(4-hydroxyphenyl)ethane,tri-(4-hydroxyphenyl)phenylmethane,2,2-bis-[4,4-bis-(4-hydroxyphenyl)cyclohexyl]propane,2,4-bis-(4-hydroxyphenylisopropyl)phenol,tetra-(4-hydroxyphenyl)methane,2,6-bis-(2-hydroxy-5-methylbenzyl)-4-methylphenol,2-(4-hydroxyphenyl)-2-(2,4-dihydroxyphenyl)propane,tetra-(4-[4-hydroxyphenylisopropyl]phenoxy)methane,1,4-bis[4,4′-dihydroxytriphenyl)methyl]benzene, in quantities of 0.01 to1.0 mol %, relative to diphenols used. Phenolic branching agents may beintroduced initially with the diphenols, acid chloride branching agentsmay be introduced together with the acid dichlorides.

The proportion of carbonate structural units in the thermoplastic,aromatic polyester carbonates may be varied at will. The proportion ofcarbonate groups is preferably up to 100 mol %, in particular up to 80mol %, particularly preferably up to 50 mol %, relative to the sum ofester groups and carbonate groups. Both the ester and carbonatefractions of the aromatic polyester carbonates may be present in theform of blocks or randomly distributed in the polycondensation product.

The relative solution viscosity (η_(rel)) of the aromatic polycarbonatesand polyester carbonates is in the range from 1.18 to 1.4, preferablyfrom 1.22 to 1.3 (measured on solutions of 0.5 g of polycarbonate orpolyester carbonate in 100 ml of methylene chloride solution at 25° C.).

The thermoplastic, aromatic polycarbonates and polyester carbonates maybe used alone or as any desired mixture with each other.

Component B

Component B comprises one or more graft polymers of

B.1 5 to 95, preferably 30 to 80 wt. %, of at least one vinyl monomer on

B.2 95 to 5, preferably 70 to 20 wt. %, of one or more graftingbackbones having glass transition temperatures of <10° C., preferably of<0° C., particularly preferably of <−20° C.

The grafting backbone B.2 generally has an average particle size (d₅₀value) of 0.05 to 5 μm, preferably of 0.10 to 0.5 μm, particularlypreferably of 0.20 to 0.40 μm.

Monomers B.1 are preferably mixtures of

B.1.1 50 to 99 parts by weight of vinyl aromatics and/orring-substituted vinyl aromatics (such as for example styrene,α-methylstyrene, p-methylstyrene, p-chlorostyrene) and/or (meth)acrylicacid (C₁-C₈)-alkyl esters (such as for example methyl methacrylate,ethyl methacrylate) and

B.1.2 1 to 50 parts by weight of vinyl cyanides (unsaturated nitritessuch as acrylonitrile and methacrylonitrile) and/or (meth)acrylic acid(C₁-C₈)-alkyl esters (such as for example methyl methacrylate, n-butylacrylate, t-butyl acrylate) and/or derivatives (such as anhydrides andimides) of unsaturated carboxylic acids (for example maleic anhydrideand N-phenylmaleimide).

Preferred monomers B.1.1 are selected from among at least one of themonomers styrene, α-methylstyrene and methyl methacrylate, preferredmonomers B.1.2 are selected from among at least one of the monomersacrylonitrile, maleic anhydride and methyl methacrylate.

Particularly preferred monomers are B.1.1 styrene and B.1.2acrylonitrile.

Grafting backbones B.2 suitable for the graft polymers B are for examplediene rubbers, EP(D)M rubbers, i.e. those based on ethylene/propyleneand optionally diene, acrylate, polyurethane, silicone, chloroprene andethylene/vinyl acetate rubbers.

Preferred grafting backbones B.2 are diene rubbers (for example based onbutadiene, isoprene etc.) or mixtures of diene rubbers or copolymers ofdiene rubbers or mixtures thereof with further copolymerisable monomers(for example according to B.1.1 and B.1.2), preferably butadiene/styrenecopolymers, providing that the glass transition temperature of componentB.2 is <10° C., preferably <0° C., particularly preferably <−10° C.

Pure polybutadiene rubber is particularly preferred.

Particularly preferred polymers B are, for example, ABS polymers(emulsion, bulk and suspension ABS), as are described for example inDE-OS 2 035 390 (=U.S. Pat. No. 3,644,574) or in DE-OS 2 248 242 (=GBpatent 1 409 275) or in Ullmann, Enzyklopädie der Technischen Chemie,volume 19 (1980), pp. 280 et seq. The gel content of the graftingbackbone B.2 is at least 30 wt. %, preferably at least 40 wt. %(measured in toluene).

The graft copolymers B are produced by free-radical polymerisation, forexample by emulsion, suspension, solution or bulk polymerisation,preferably by emulsion polymerisation or bulk polymerisation.

Particularly suitable graft rubbers are ABS polymers which are producedby redox initiation using an initiator system comprising organichydroperoxide and ascorbic acid according to U.S. Pat. No. 4,937,285.

Since, as is known, the graft monomers are not necessarily grafted intheir entirety onto the grafting backbone during the grafting reaction,graft polymers B are also taken according to the invention to includethose products which are obtained by (co)polymerisation of the graftmonomers in the presence of the grafting backbone and are also isolatedduring working up.

Suitable polymer B acrylate rubbers B.2 are preferably polymers preparedfrom acrylic acid alkyl esters, optionally with up to 40 wt. %, relativeto B.2, of other polymerisable, ethylenically unsaturated monomers.Preferred polymerisable acrylic acid esters include C₁-C₈ alkyl esters,for example methyl, ethyl, butyl, n-octyl and 2-ethylhexyl esters;haloalkyl esters, preferably halo-C₁-C₈-alkyl esters, such aschloroethyl acrylate and mixtures of these monomers.

Monomers having more than one polymerisable double bond may also becopolymerised for crosslinking purposes. Preferred examples ofcrosslinking monomers are esters of unsaturated monocarboxylic acidshaving 3 to 8 C atoms and unsaturated monohydric alcohols having 3 to 12C atoms, or saturated polyols having 2 to 4 OH groups and 2 to 20 Catoms, such as for example ethylene glycol dimethacrylate, allylmethacrylate; polyunsaturated heterocyclic compounds, such as forexample trivinyl and triallyl cyanurate; polyfunctional vinyl compounds,such as di- and trivinylbenzenes; as well as triallyl phosphate anddiallyl phthalate.

Preferred crosslinking monomers are allyl methacrylate, ethylene glycoldimethacrylate, diallyl phthalate and heterocyclic compounds having atleast three ethylenically unsaturated groups.

Particularly preferred crosslinking monomers are the cyclic monomerstriallyl cyanurate, triallyl isocyanurate,triacryloylhexahydro-s-triazine, triallylbenzenes. The quantity ofcrosslinking monomers is preferably 0.02 to 5, preferably 0.05 to 2 wt.%, relative to the grafting backbone B.2.

It is advantageous to limit the quantity of cyclic crosslinking monomershaving at least three ethylenically unsaturated groups to below 1 wt. %of the grafting backbone B.2.

Preferred “other” polymerisable, ethylenically unsaturated monomerswhich, in addition to the acrylic acid esters, may optionally be used toproduce the grafting backbone B.2 are, for example, acrylonitrile,styrene, α-methylstyrene, acrylamides, vinyl C₁-C₆-alkyl ethers, methylmethacrylate, butadiene. Preferred acrylate rubbers as the graftingbackbone B.2 are emulsion polymers having a gel content of at least 60wt. %.

Further suitable grafting backbones B.2 are silicone rubbers havingactive grafting sites, as are described in DE-OS 3 704 657, DE-OS 3 704655, DE-OS 3 631 540 and DE-OS 3 631 539.

The gel content of the grafting backbone B.2 is determined in a suitablesolvent at 25° C. (M. Hoffmann, H. Krömer, R. Kuhn, Polymeranalytik I &II, Georg Thieme Verlag, Stuttgart 1977).

The average particle size d₅₀ is the diameter both above and below which50 wt. % of the particles lie. This value may be measured byultracentrifugation (W. Scholtan, H. Lange, Kolloid Z. und Z. Polymere,250 (1972), 782-1796).

Component C

Component C comprises one or more thermoplastic vinyl (co)polymers C.1.and/or polyalkylene terephthalates C.2.

Suitable vinyl (co)polymers C.1 are polymers of at least one monomerfrom the group of vinyl aromatics, vinyl cyanides (unsaturatednitrites), (meth)acrylic acid (C₁-C₈)-alkyl esters, unsaturatedcarboxylic acids as well as derivatives (such as anhydrides and imides)of unsaturated carboxylic acids. Particularly suitable (co)polymers arethose prepared from

C.1.1 50 to 99, preferably 60 to 80 parts by weight of vinyl aromaticsand/or ring-substituted vinyl aromatics (such as for example styrene,α-methylstyrene, p-methylstyrene, p-chlorostyrene) and/or (meth)acrylicacid (C₁-C₈)-alkyl esters (such as or example methyl methacrylate, ethylmethacrylate) and

C.1.2 1 to 50, preferably 20 to 40 parts by weight of vinyl cyanides(unsaturated nitrites) such as acrylonitrile and methacrylonitrileand/or (meth)acrylic acid (C₁-C₈)-alkyl esters (such as for examplemethyl methacrylate, n-butyl acrylate, t-butyl acrylate) and/orunsaturated carboxylic acids (such as maleic acid) and/or derivatives(such as anhydrides and imides) of unsaturated carboxylic acids (forexample maleic anhydride and N-phenylmaleimide).

The (co)polymers C.1 are resinous, thermoplastic and rubber-free.

The copolymer of C.1.1 styrene and C.1.2 acrylonitrile is particularlypreferred.

The (co)polymers C.1 are known and may be produced by free-radicalpolymerisation, in particular by emulsion, suspension, solution or bulkpolymerisation. The (co)polymers preferably have molecular weights{overscore (M)}_(w) (weight average, determined by light scattering orsedimentation) of between 15000 and 200000.

The component C.2 polyalkylene terephthalates are reaction products ofaromatic dicarboxylic acids or the reactive derivatives thereof, such asdimethyl esters or anhydrides, and aliphatic, cycloaliphatic oraraliphatic diols, together with mixtures of these reaction products.

Preferred polyalkylene terephthalates contain at least 80 wt. %,preferably at least 90 wt. %, relative to the dicarboxylic acidcomponent, of terephthalic acid residues and at least 80 wt. %,preferably at least 90 mol %, relative to the diol component, ofethylene glycol and/or 1,4-butanediol residues.

In addition to terephthalic acid residues, the preferred polyalkyleneterephthalates may contain up to 20 mol %, preferably up to 10 mol %, ofresidues of other aromatic or cycloaliphatic dicarboxylic acids having 8to 14 C atoms or aliphatic dicarboxylic acids having 4 to 12 C atoms,such as for example residues of phthalic acid, isophthalic acid,2,6-naphthalenedicarboxylic acid, 4,4′-diphenyldicarboxylic acid,succinic acid, adipic acid, sebacic acid, azelaic acid,cyclohexanediacetic acid.

In addition to ethylene glycol or 1,4-butanediol residues, the preferredpolyalkylene terephthalates may contain up to 20 mol %, preferably up to10 mol %, of other aliphatic diols having 3 to 12 C atoms orcycloaliphatic diols having 6 to 21 C atoms, for example residues of1,3-propanediol, 2-ethyl-1,3-propanediol, neopentyl glycol,1,5-pentanediol, 1,6-hexanediol, 1,4-cyclohexanedimethanol,3-ethyl-2,4-pentanediol, 2-methyl-2,4-pentanediol,2,2,4-trimethyl-1,3-pentanediol, 2-ethyl-1,3-hexanediol, 2,2-diethyl-1,3-propanediol, 2,5-hexanediol, 1,4-di-(β-hydroxyethoxy)benzene,2,2-bis-(4-hydroxycyclohexyl)propane,2,4-dihydroxy-1,1,3,3-tetramethylcyclobutane,2,2-bis-(4-β-hydroxyethoxyphenyl)propane and2,2-bis-(4-hydroxypropoxyphenyl)propane (DE-OS 2 407 674, 2 407 776, 2715 932).

The polyalkylene terephthalates may be branched by incorporatingrelatively small quantities of tri- or tetrahydric alcohols or tri- ortetrabasic carboxylic acids, for example according to DE-OS 1 900 270and U.S. Pat. No. 3,692,744. Examples of further preferred branchingagents are trimesic acid, trimellitic acid, trimethylolethane andtrimethylolpropane and pentaerythritol.

Particularly preferred polyalkylene terephthalates are those solelyproduced from terephthalic acid and the reactive derivatives thereof(for example the dialkyl esters thereof) and ethylene glycol and/or1,4-butanediol, and mixtures of these polyalkylene terephthalates.

Mixtures of polyalkylene terephthalates contain 1 to 50 wt. %,preferably 1 to 30 wt. %, of polyethylene terephthalate and 50 to 99 wt.%, preferably 70 to 99 wt. %, of polybutylene terephthalate.

The preferably used polyalkylene terephthalates generally have anintrinsic viscosity of 0.4 to 1.5 dl/g, preferably of 0.5 to 1.2 dl/g,measured in phenol/o-dichlorobenzene (1:1 parts by weight) at 25° C. ina Ubbelohde viscosimeter.

The polyalkylene terephthalates may be produced using known methods(c.f. for example Kunststoff-Handbuch, volume VIII, pp. 695 et seq.,Carl Hanser Verlag, Munich 1973).

Component D

The moulding compositions according to the invention contain phosphoruscompounds according to formula (I) as flame retardants,

in which the residues have the above-stated meanings.

The component D phosphorus compounds which are suitable according to theinvention are generally known (c.f. for example Ullmanns Encyklopädieder technischen Chemie, volume 18, pp. 301 et seq., 1979; Houben-Weyl,Methoden der organischen Chemie, volume 12/1, page 43; Beilstein, volume6, page 177).

Preferred substituents R¹ to R⁴ comprise methyl, butyl, octyl,chloroethyl, 2-chloropropyl, 2,3-dibromopropyl, phenyl, cresyl, cumyl,naphthyl, chlorophenyl, bromophenyl, pentachlorophenyl andpentabromophenyl. Methyl, ethyl, butyl, phenyl and naphthyl areparticularly preferred.

The aromatic groups R¹, R², R³ and R⁴ may be substituted with halogenand/or C₁-C₄ alkyl. Particularly preferred aryl residues are cresyl,phenyl, xylenyl, propylphenyl or butylphenyl as well as the brominatedand chlorinated derivatives thereof.

R⁵ and R⁶ mutually independently preferably mean methyl or bromine.

Y preferably denotes C₁-C₇ alkylene, in particular isopropylidene ormethylene.

n in the formula (I) may mutually independently be 0 or 1, n preferablyequals 1.

q may be 0, 1, 2, 3 or 4, q is preferably 0, 1 or 2, q particularlypreferably equals 0.

N may assume values of 0.9 to 10, preferably of 0.95 to 5, in particularof 1 to 3. Mixtures of various phosphates may also be used as componentD according to the invention. In this case, N has an average value.Monophosphorus compounds (N=0) may also be present in this mixture.

The average N values may, be determined by using suitable methods [gaschromatography (GC), high pressure liquid chromatography (HPLC), gaspermeation chromatography (GPC)] to determine the composition of thephosphate mixture (molecular weight distribution) and calculatingtherefrom the average values for N.

Component E

Fluorinated polyolefins may be added as a further component.

The fluorinated polyolefins E are of a high molecular weight and haveglass transition temperatures of above −30° C., generally of above 100°C., fluorine contents preferably of 65 to 76, in particular of 70 to 76wt. %, average particle diameters d₅₀ of 0.05 to 1000, preferably of0.08 to 20 μm. The fluorinated polyolefins E generally have a density of1.2 to 2.3 g/cm³. Preferred fluorinated polyolefins E arepolytetrafluoroethylene, polyvinylidene fluoride,tetrafluoroethylene/hexafluoropropylene and ethylene/tetrafluoroethylenecopolymers. The fluorinated polyolefins are known (c.f. Vinyl & RelatedPolymers by Schildknecht, John Wiley & Sons Inc., New York, 1962, pp.484-494; Fluoropolymers by Wall, Wiley-Interscience, John Wiley & SonsInc., New York, volume 13, 1970, pp. 623-654; Modern PlasticsEncyclopedia, 1970-1971, volume 47, no. 10 A, October 1970, McGraw-HillInc., New York, pp. 134 and 774; Modern Plastics Encyclopedia,1975-1976, October 1975, volume 52, no. 10A, McGraw-Hill Inc., New York,pp. 27, 28 and 472 and U.S. Pat. Nos. 3,671,487, 3,723,373 and3,838,092).

They may be produced using known processes, thus for example bypolymerising tetrafluoroethylene in an aqueous medium with afree-radical forming catalyst, for example sodium, potassium or ammoniumperoxydisulfate, at pressures of 7 to 71 kg/cm² and at temperatures of 0to 200° C., preferably at temperatures of 20 to 100° C. (c.f. forexample U.S. Pat. No. 2,393,967 for further details). Depending upon theform in which they are used, the density of these materials may bebetween 1.2 and 2.3 g/cm³, the average particle size between 0.5 and1000 μm.

Fluorinated polyolefins E preferred according to the invention are usedin the form of an emulsion having average particle diameters of 0.05 to20 μm, preferably of 0.08 to 10 μm, and a density of 1.2 to 1.9 g/cm³,or in the form of powder having average particle diameters of 100 to1000 μm and densities of 2.0 g/cm³ to 2.3 g/cm³.

The fluorinated polyolefins E are used according to the invention in theform of special preparations:

E.1) as a coagulated mixture with at least one of components A to C,wherein the fluorinated polyolefin E or polyolefin mixture is mixed asan emulsion with at least one emulsion of components A to C and thencoagulated,

or

E.2) as a precompound with at least one of components A to C, whereinthe fluorinated polyolefins E are mixed as a powder with a powder orpellets of at least one of components A to C and melt-compounded,generally at temperatures of 200° C. to 330° C., in conventional unitssuch as internal kneaders, extruders or twin-screw extruders.

Preferred preparations for the fluorinated polyolefins E are coagulatedmixtures with a graft polymer B or a vinyl (co)polymer C.

A coagulated mixture is produced from B and E by first mixing an aqueousemulsion (latex) of a graft polymer B with a finely divided emulsion ofa tetrafluoroethylene polymer E; suitable tetrafluoroethylene polymeremulsions conventionally have solids contents of 30 to 70 wt. %, inparticular of 50 to 60 wt. %, preferably of 30 to 35 wt. %.

The quantity of component A, B and C stated in the description does notinclude the proportion of the graft polymer, vinyl (co)polymer orpolycarbonate for the coagulated mixture according to E.1 and E.2.

In the emulsion mixture, the equilibrium ratio of graft polymer B or(co)polymers to the fluorinated polyolefin E is 95:5 to 60:40,preferably 90:10 to 50:50. The emulsion mixture is then coagulated in aknown manner, for example by spray drying, freeze drying or coagulationby addition of inorganic or organic salts, acids, bases or organic,water-miscible solvents, such as alcohols, ketones, preferably attemperatures of 20 to 150° C., in particular of 50 to 100° C. Ifnecessary, drying may be performed at 50 to 200° C., preferably at 70 to100° C.

Suitable tetrafluoroethylene polymer emulsions are conventionalcommercial products and are offered for sale, for example, by DuPont(Wilmington, Del., USA) as Teflon® 30 N or by Dyneon GmbH (Burgkichen,Germany) as Hostaflon®.

Preferred preparations for the fluorinated polyolefins E are furthermoreprecompounds with a polycarbonate A or a graft polymer B or a vinyl(co)polymer C.

In the precompound, the ratio of component A, B or C to the fluorinatedpolyolefin E is 95:5 to 60:40, preferably 90:10 to 50:50.

Suitable fluorinated polyolefin powders are conventional commercialproducts and are offered for sale, for example, by DuPont as Teflon® CFP6000 N or by Dyneon GmbH (Burgkichen, Germany) as Hostaflon® TF 2071.

The moulding compositions according to the invention may contain atleast one of the conventional additives, such as lubricants and mouldrelease agents, for example pentaerythritol tetrastearate, nucleatingagents, anti-static agents, stabilisers, fillers and reinforcingmaterials as well as dyes and pigments.

The filled or reinforced moulding compositions may contain up to 60,preferably 10 to 40 wt. %, relative to the filled or reinforced mouldingcomposition, of fillers and/or reinforcing materials. Preferredreinforcing materials are glass fibres. Preferred fillers, which mayalso have a reinforcing action, are glass beads, mica, silicates,quartz, talcum, titanium dioxide, wollastonite.

The moulding compositions according to the invention may contain up to35 wt. %, relative to the overall moulding composition, of a further,optionally synergistic flame retardant. Examples of further flameretardants which may be mentioned are organic halogen compounds, such asdecabromobisphenyl ether, tetrabromobisphenol, inorganic halogencompounds such as ammonium bromide, nitrogen compounds, such asmelamine, melamine/formaldehyde resins, inorganic hydroxide compounds,such as Mg, Al hydroxide, inorganic compounds such as antimony oxides,barium metaborate, hydroxoantimonate, zirconium oxide, zirconiumhydroxide, molybdenum oxide, ammonium molybdate, zinc borate, ammoniumborate, barium metaborate, talcum, silicate, silicon oxide and tinoxide, as well as siloxane compounds. Monophosphate compounds,oligomeric phosphate compounds or mixtures thereof may additionally beused as flame retardants. Such phosphorus compounds are described inEP-A 363 608, EP-A 345 522 and DE-OS 197 21 628.

The moulding compositions according to the invention containingcomponents A to E and optionally further known additives such asstabilisers, dyes, pigments, lubricants and mould release agents,nucleating agents, as well as antistatic agents, fillers and reinforcingmaterials are produced by mixing the particular constituents in a knownmanner and melt-compounding and melt-extruding them at temperatures of200° C. to 300° C. in conventional units such as internal kneaders,extruders and twin-screw extruders.

The individual constituents may be mixed in a known manner both insuccession and simultaneously and both at approx. 20° C. (roomtemperature) and at a higher temperature.

The present invention accordingly also provides a process for theproduction of the moulding compositions.

The moulding compositions of the present invention may be used for theproduction of mouldings of any kind. Mouldings may in particular beproduced by injection moulding. Examples of mouldings which may beproduced are: casings of all kinds, for example for domestic appliancessuch as juice extractors, coffee machines, food mixers, for officeequipment, such as monitors, printers, copiers or cladding sheet for thebuilding sector and automotive components. They may also be used inelectrical engineering applications as they have very good electricalproperties.

The moulding compositions according to the invention may furthermore,for example, be used to produce the following mouldings or shapedarticles:

1. Interior trim for rail vehicles

2. Hub-caps

3. Casings for electrical devices containing small transformers

4. Casings for information dissemination and transmission devices

5. Casings and cladding for medical purposes

6. Massage devices and casings therefor

7. Toy vehicles for children

8. Sheet wall elements

9. Casings for safety equipment

10. Hatchback spoilers

11. Thermally insulated transport containers

12. Apparatus for keeping or caring for small animals

13. Mouldings for sanitary and bathroom installations

14. Cover grilles for ventilation openings

15. Mouldings for summer houses and sheds

16. Casings for garden appliances.

Another processing method is the production of mouldings bythermoforming of previously produced sheet or film.

The present invention accordingly also provides the use of the mouldingcompositions according to the invention for the production of mouldingsof all kinds, preferably those stated above, and the mouldings made fromthe moulding compositions according to the invention.

EXAMPLES Component A

Bisphenol A based polycarbonate having a relative solution viscosity of1.278, measured in methylene chloride at 25° C. and a concentration of0.5 g/100 ml.

Component B

Graft polymer of 40 parts by weight of styrene and acrylonitrile in a73:27 ratio on 60 parts by weight of particulate crosslinkedpolybutadiene rubber (average particle diameter d₅₀=0.28 μm), producedby emulsion polymerisation.

Component C

Styrene/acrylonitrile copolymer having a styrene:acrylonitrile ratio of72:28 and an intrinsic viscosity of 0.55 dl/g (measured indimethylformamide at 20° C.).

Component D

The average N value was determined by firstly determining theproportions of the monomeric and oligomeric phosphates by HPLCmeasurements:

Column type: LiChrosorp RP-8

Eluent in the gradient: Acetonitrile/water 50:50 to 100:0

Contentration: 5 mg/ml

The number-weighted averages are then determined in known manner fromthe proportions of the individual constituents (mono andoligophosphates).

Component E

E.1 (Comparison)

PTFE-powder Teflon CFP 6000 N (DuPont, Wilmington, Del., USA)

E.2

Coagulated mixtures prepared from 90 parts by weight of graft polymer(of 40 parts by weight of styrene and acrylonitrile in a ratio of 73:27on 60 parts by weight of particulate crosslinked polybutadiene rubberhaving an average particle diameter d₅₀=0.28 μm) and 10 parts by weightof polytetrafluoroethylene polymer (Teflon® 30 N).

E.3

Coagulated mixture prepared from 80 parts by weight of graft polymer (asE.2) and 20 parts by weight of polytetrafluoroethylene polymer (Teflon®30 N).

E.4

Coagulated mixture prepared from 50 parts by weight of vinyl (co)polymer(of styrene and acrylonitrile in a ratio of 72:28, intrinsic viscosityof 0.85 dl/g measured in dimethylformamide at 20° C.) and 50 parts byweight of polytetrafluoroethylene polymer (Teflon® 30 N).

E.5

Precompound prepared from 80 parts by weight of graft polymer (of 84parts by weight of styrene and acrylonitrile in a ratio of 72:28 on 16parts by weight of crosslinked butadiene rubber) and 20 parts by weightof polytetrafluoroethylene polymer (Teflon® CFP 6000 N).

E.6

Precompound prepared from 90 parts by weight of vinyl (co)polymer (ofstyrene and acrylonitrile in a ratio of 72:28, intrinsic viscosity of0.55 dl/g measured in dimethylformamide at 20° C.) and 10 parts byweight of polytetrafluoroethylene polymer (Teflon® CFP 6000 N).

E.7

Precompound prepared from 90 parts by weight of polycarbonate (based onbisphenol A having a relative solution viscosity of 1.278, measured inmethylene chloride at 25° C. and a concentration of 0.5 g/100 ml) and 10parts by weight of polytetrafluoroethylene polymer (Teflon® CFP 6000 N).

Production and Testing of the Moulding Compositions According to theInvention

The components are mixed with conventional processing auxiliaries in aZSK 32 twin screw extruder. The mouldings are produced at 260° C. on anArburg model 270 E injection moulding machine.

Notched impact strength is determined in accordance with method ISO 180IA on bars of dimensions 80×10×4 mm³ at room temperature.

The Vicat B softening point is determined according to DIN 53 460 onbars of dimensions 80×10×4 mm³.

Elongation at break is determined according to ISO 527/DIN 53 457.

Flame retardancy is determined according to UL 94V.

Stress cracking behaviour (ESC behaviour) is investigated on bars ofdimensions 80×10×4 mm³, injection moulding temperature 260° C. The testmedium used is a mixture of 60 vol. % toluene and 40 vol. % isopropanol.The test pieces are pre-stressed on a circular arc template (initialelongation ε_(x) in percent) and immersed in the test medium at roomtemperature. Stress cracking behaviour is evaluated on the basis ofcracking or failure as a function of initial elongation in the testmedium.

TABLE 1 Composition and properties of moulding compositions 1 (Comp.) 23 4 5 6 7 Components [parts by weight] A 68.4 68.4 68.4 68.4 68.4 68.464.8 B 9.4 5.8 7.8 9.4 8.9 9.0 9.4 C 9.3 9.3 9.3 8.9 8.1 5.7 9.3 D 12.51.25 12.5 12.5 12.5 12.5 12.5 E.1 0.4 E.2 — 4.0 — — — — E.3 — — 2.0 — —— E.4 — — — 0.8 — — E.5 — — — — 2.0 — E.6 — — — — — 4.0 — E.7 — — — —4.0 Properties: Vicat B 120 102 103 103 103 103 102 103 [° C.] a_(k) ISO180 1A 42 47 50 48 48 46 45 [kJ/m²] Elongation at 35 56 58 65 75 70 68break [%] ESC behaviour, 1.8 2.0 2.4 2.4 2.4 2.0 2.0 failure at ε_(x)[%] UL 94 V at 1.6 mm Rating V-2 V-0 V-0 V-0 V-0 V-0 V-0 Total burn time47 29 27 22 19 28 26 [sec]

The moulding compositions according to the invention, i.e. those whichwere produced from special PTFE preparations, are distinguished bydistinctly improved mechanical properties (notched impact strength(a_(k)), elongation at break), greater stress cracking resistance aswell as improved flame retardancy in accordance with the UL 94 V test(reduction of formation of burning droplets, reduced burn time). Havingthis range of properties, the moulding compositions according to theinvention are in particular suitable for flame resistant housingcomponents of a complicated geometry which are mechanically stressed andexposed to materials.

What is claimed is:
 1. A molding composition comprising: A) 40 to 99parts by weight of at least one of aromatic polycarbonate or polyestercarbonate; B) 0.5 to 60 parts by weight of graft polymer prepared from,B.1) 5 to 95 wt. % of one or more vinyl monomers, and B.2) 95 to 5 wt. %of one or more grafting backbones having a glass transition temperatureof <10° C.; C) 0 to 45 parts by weight of at least one thermoplasticpolymer selected from the group consisting of vinyl (co)polymers andpolyalkylene terephthalates; D) 0.5 to 20 parts by weight of aphosphorus compound represented by formula (I)

 in which R¹, R², R³ and R⁴ are mutually independently C₁-C₈ alkyl,optionally substituted by halogen, C₅-C₆ cycloalkyl, C₆-C₁₀ aryl orC₇-C₁₂ aralkyl, each optionally substituted by halogen or alkyl, orboth, n are mutually independently 0 or 1, q are mutually independently0, 1, 2, 3 or 4, N is 0.9 to 10, R⁵ and R⁶ mutually independently meanC₁-C₄ alkyl or halogen, Y means C₁-C₇ alkylidene, C₁-C₇ alkylene, C₅-C₁₂cycloalkylene, C₅-C₁₂ cycloalkylidene, —O—, —S—, —SO—, —SO₂— or —CO—;and E) a fluorinated polyolefin in a form selected from the groupconsisting of one of, (i) a coagulated mixture of said fluorinatedpolyolefin and at least one component selected from the group consistingof component (A) and component (C), said coagulated mixture being formedby mixing an emulsion of said fluorinated polyolefin with at least oneof an emulsion of component (A) or an emulsion of component (C),followed by coagulation thereof, or (ii) a precompound of saidfluorinated polyolefin and at least one component selected from thegroup consisting of component (A), component (B) and component (C), saidprecompound being formed by dry mixing one of said fluorinatedpolyolefin in powder form and said fluorinated polyolefin in pelletizedform with at least one of components (A), (B) or (C), or meltcompounding the dry mixture.
 2. Moulding compositions according to claim1 wherein N in the formula (I) denotes an average value of 0.95 to
 5. 3.Moulding compositions according to claim 1 wherein N in the formula (I)denotes an average value of 1 to
 3. 4. Moulding compositions accordingto claim 1, containing as the vinyl monomers B.1 mixtures of, B.1.1 50to 99 parts by weight of at least one monomer selected from the groupconsisting of vinyl aromatics, ring-substituted vinyl aromatics, and(meth)acrylic acid (C₁-C₈)-alkyl esters, and B.1.2 1 to 50 parts byweight of at least one monomer selected from the group consisting ofvinyl cyanides, (meth)acrylic acid (C₁-C₈)-alkyl esters, and imides oranhydrides of unsaturated carboxylic acids.
 5. Moulding compositionsaccording to claim 1 wherein said grafting backbone B.2 is selected fromat least one member of the group consisting of diene rubber, acrylaterubber, silicone rubber and ethylene/propylene/diene rubber.
 6. Mouldingcompositions according to claim 1 wherein Y in the formula (I) denotesisopropylidene or methylene.
 7. Moulding compositions according to claim6, wherein Y in the formula (I) denotes isopropylidene.
 8. Mouldingcompositions according to claim 1 wherein the vinyl (co)polymers of (C)are prepared from at least one monomer selected from the groupconsisting of vinyl aromatics, vinyl cyanides, (meth)acrylic acid(C₁-C₈)-alkyl esters, unsaturated carboxylic acids, and imides oranhydrides of unsaturated carboxylic acids.
 9. Moulding compositionsaccording to claim 1 further containing at least one additive selectedfrom the group consisting of stabilisers, pigments, mould releaseagents, flow auxiliaries, antistatic agents, fillers and reinforcingmaterials.
 10. A method of forming a moulded article comprising: (a)providing the moulding compositions according to claim 1; and (b)injection moulding said composition, thereby forming said mouldedarticle.
 11. Mouldings prepared from moulding compositions according toclaim
 1. 12. The molding composition of claim 1 wherein said fluorinatedpolyolefin is in the form of said precompound (E)(ii), which consistsessentially of said fluorinated polyolefin and graft copolymer (B). 13.The molding composition of claim 1 wherein said fluorinated polyolefinis in the form of said precompound (E)(ii), which consists essentiallyof said fluorinated polyolefin and component (C).
 14. The moldingcomposition of claim 1 wherein said fluorinated polyolefin (E) ispresent in an amount of from 0.01 to 3 parts by weight, and saidprecompound (E)(ii) contains said fluorinated polyolefin in an amount of5 to 40 percent by weight, based on the weight of said precompound, andat least one of components (A), (B) and (C) in an amount totaling 60 to95 percent by weight, based on the weight of said precompound.